Tha best Irish stew I made was when Sainsburys had mutton and goat on offer. I didn't try the goat, and the two then vanished and have not been seen again. But the mutton gave a real depth to the flavour compared with lamb. I made the simple version, onion, potato, meat and seasoning, not the extended can't tell it from any other stew that lurks in ready meals and umpteen recipes online. I wanted to try mutton in Lancashire hotpot too, but no more mutton on sale.